Treatment of hydrocarbons



50pl- 11, 1945- c. L. THOMAS Erm.

TREATMENT OF HYDROCARBONS Filed Aug. 14, 1942 mix Patented Sept. 1l,1945 2.384,5.5 TREATMENT l' HYDBOCABBONS charleslslhomaoandollmllhalclgnorsto 00mm, Chicas. Ill..

Application August 14, 1942, Serial No. 454,834

(Cl. zot-671) 14 Claims.

This is a. continuation-impart oi our eo-pe'nding application Serial No.257.464, filed February 20, 1939.

This invention relates to the manufacture o! alkylated aromatichydrocarbons, and in a more specific sense has reference to a process o!contacting aromatic hydrocarbon with alcohols in the presence ofspeciilc catalysts under specific operating conditions.

The invention is characterized by the reaction of aromatica 'withalcohols. the use of silica-base type catalysts, and speciilctemperature time and pressure conditions ci operation. In addition, thepresent invention includes a number of other features which will behereinafter set forth in detail.

It has heretofore been suggested that aromatic hydrocarbons may bereacted with alcohols to produce alkylated aromatica. For example. inUnited States Patent No. 1,908,190, broad statements are made that thisreaction may be eilected in the presence of catalysts containing silicaand alumina. However, the examples cited in the above patent aredirected to the reaction of benzene with cyclohexanol and benzyl alcoholand the reaction of phenol and aniline with methyl alcohol. In theseexamples the time of contact varies from 6 hours to 15 hours. Times ofcontact oi B hours or more are impractical for commercial use incontinuous operations. Obviously the examples cited above are based onbatch operations and do not teach a continuous process for commercialoperation. It is an object of the present invention to shorten thereaction time so as to provide a continuous process for accomplishingthese results, which process may be readily adapted to commercialoperations.

As a feature oi the invention, the times of contact employed are lessthan 15 minutes. By contact time. as used in the present specication andclaims, is meant the residence time of the reactants in the reactionzone when calculated on the basis oi! an empty vessel under theconditions of operation prevailing therein. Usually the contact timewill be less than l minutes, hut as an essential feature of thisinvention, the contact time will never exceed minutes.

In addition to the above features. the invention discloses the featureof utilizing an excess oi' aromatics in the reaction zone. Thisoperation has a number of advantages. the primary ones being (i)conducting the reactions under substantially adiabatic conditions and(2) dissolving the unconverted ethylene in the aromatica for recycling.These and other advantages o! this particular method of operation willbe hereinafter described in detail.

It is believed that in the reaction of alcohols with aromatica. thealcohols are nrst dehydrated under the conditions of operation to yieldwater and oleiins, and that the aromatica are then alkylated by theoledns. A particular advantage in the use of alcohols as one of thereactants is that the dehydration reaction is endothermic and absorbsheat, while the alkylation reaction is exothermic and liberates heat.Thus, the heat llberated by the exotherxnic alkylation reaction isutilized in the endothermic dehydration reaction, and this effects anemcient thermal system and, at the same time. also aids in permittingthe production of alkylated aromatics to be eiiected xmder substantiallyadiabatic conditions.

Likewise, by operating according to the teachings of the presentinvention, the yields of desired mono-alkylated products are increased.and the production oi undesired higher boiling polyalkylated aromatlcsare reduced to a minimum.

In one specific embodiment the present invention relates to a continuousprocess for producing alkylated aromatics which comprises reacting anaromatic with an alcohol in the presence of a catalyst containing silicaand alumina for a time of contact oi less than l5 minutes.

The catalysts employed in the present process are of the silica basetype and comprise com ltes oi silica and one or more metal oxides. suchas alumina. zirconia, thoria. magnesia, etc. The catalyst may be oinatural origin and includes such substances as clays, bleaching earths,kaollns, montmcrlllonites. bentonites. feldspars. etc., which may or maynot be activated by treatment with acid or otherwise. The preferredcatalysts are. however, of synthetic origin and may be prepared by anumber of alternative methods to be hereinafter described in detail. Thesynthetically prepared catalysts have higher activity than the naturallyoccurring catalyst and, in addition, the synthetically preparedcatalysts are more stable under the higher temperatures encountered during the regeneration thereof. It is understood. however, that thevarious catalysts, either of natural or synthetic origin. which may beemployed in accordance with the present invention are not necessarilyequivalent in their activity.

According to one general method, the preferred synthetic catalyst may beprepared by precipitating silica from solution as a hydrosel andsubsequently admixing or depositing the hydrogels of alumina, zirconia,and/or thorla upon the hydrated silica. One of the more convenientdepoaitonottheseneratsuitabiebydratedsilicamaybeproducedbytheuseoidiiutesolutiom selis obtained washing are at After precipitating the bed state, but it hasbeen detertaht their removal is necessary tained suitable for progetherwith the maior portion of the multivalent salts. are removed in thewater washing treat- Some of the multivalent metals introremaining afterthe washing process driven cil' in subsequent treatment at temperatures.

elevated hydrogel by the addition o1 tion oi ammonium hydroxide. In thisexample, the alumina, zirconia, and/or thoria are co-prezirconia, and/orhydrated thoria precipitated either www hydrocarbon converaluminailluminate, for exampb, or i! zirconium and/or thorium te areprecipitated by the interaction or nitrate and/or thorium nitratodroxide, relulated mina. zirconia, and/or tb'oria.

As further alternatives in the preparation o! silica-base alkylationcatalysts. pui-ined silica sel may be added to a solution o! salts ofaluminum.

um, and/or thorium and hydrated alumina. hydrated zirconia, and/orhydrated thoria with or without the usa of heat. or the puriiied silicagel may be mixed with suitable amounts of salts of aluminum, ziroonium,and/ or thorium. as, for example. to fonn a paste and h'eated whereby a1and/or thoria are deposited upon the silica sel as a result of thedecomposition ot the alumina. zirconia. and/or thorium salts.

In the methods above described. a silica hydrogel free from alkali metalions was admixed or had deposited thereon relatively pure hydratedalumina. hydrated zirconia, and/or hydrated thoria prior to the dryingtreatment. ods described below. the hydrated alumina, hydrated zirconia,and/or hydrated thoria are concurrently precipitated or admixed andtreated to remove the alkali metal ions from the composited materialprior to drying treatment. either in the presence oi' the originalreactants or subsequent to water washing. Thus. solutions of siliconcompounds. more usually alkali metal silicates and soluble aluminum,zirconium, and/or thorium salts may be mixed under regulated conditionsof acidity or basicity to jointly precipitate hydrated silica. hydratedalumina, hydrated zirconia, and/or hy drated thoria in varyingproportions. For example, solutions of sodium silicate, aluminiumchloride, zirconyl nitra and/or thorium nitrate may be mixed and analkaline or acid reagent added according to the proportions used so thatin the mix a pH in the range of 3-10 is obtained. In cases where a solis formed, the precipitation may be brought about if the sol is acid bythe addition of a volatile base. as for example, ammonium hydroxide, andalkali metal salts removed by water washing, or the composite may betreated as indicated above in connection with the purincation of thehydrated silica to remove alkali Various methods are possible for thepreparation of the hydrated silica, hydrated mounts.

The character and eillciency of the ultimately prepared silica catalystsupports will vary more or less with precipitation and/or mixing.purification treatment. ratio of components. calbe reactivated rapidlyby passing eining. etc. The ratio of tbe components may be varied withinwide limits. the limiting factor being more in evidence with respect tosmall proportions than with large proportions of the various components.In general, it appears that 2-0 mole per cent of alumina, zirconia,and/or thoria together with reference to silica may be considered anapproximation oi the minimum proportions.

After the alumina, zirconia, and/or thoria have been mixed with ordeposited on the purined silica gel and water washed, i! desired, asdescribed for one general method of preparation, or after the hydratedsilica. hydrated alumina, hydrated zirconia, and/or hydrated thoria havebeen composited and treated to remove the alkali metal ions. asdescribed for another general method of preparation, the catalyticmaterials may be recovered as a iilter cake and dried at a temperaturein the order of 24o-300 F., more or less, after which they may be formedinto particles of a suitable average deilnlte size ranging from powderto various forms and sizes obtained by pressing and screening, orotherwise formed into desirable shapes by compression or extrusionmethods.

By calcining at temperature of the order of approximately 850-1000 F..mum activity of the silica-base alkylation catalyst is obtained and afurther dehydration occurs so that, for example, after a considerableperiod oi heating at 900" F., the water content, as determined byanalysis. is of the order of 2-3%.

The methods of preparing the catalyst, as heretofore described, arepreferred in connection with catalysts containing silica and alumina,silica and zirconia, silica and thoria, or mixtures thereof. However,when preparing catalysts containing silica and magnesia, a preferredmethod of operation is to prepare the silica hydrogel in any of themanners heretofore described and then composite it with magnesio bymilling the niag-l nesia into the silica hydrogel. If other metal oxidesare also to be incorporated in the composite catalyst, the other metaloxide may be added by one of the methods outlined above either before orafter the addition of magnesio.

Silica-base alkylating catalysts prepared by the various types ofprocedures outlined above evidently possess large total contact surfacescorresponding to a desirable porosity, the pores of the catalystparticles being of such size and shape that they do not become cloggedwith carbonaceous deposit after a long period of service and are,therefore, not dimcult to reactivate by oxidation. This structure isretained, also, after many alternate periods of use and reactivation, asevidenced by the fact thatthe catalysts may air or other oxidizing gasover vthe used particles to burn off the deposits of carbonaceousmaterials at temperatures above 800 Il., temperatures as high as140th-i000 F., having been reached without apparently eilecting thecatalytic activity.

The pressures used in the present process are within the broad range offrom 200 to 2000 pounds, or more, per square inch and preferably arewithin the range oi from 250 to 000 pounds per square inch. The time ofcontact, as heretofore mentioned, is less than minutes. Ii times ofcontact above l5 minutes are employed. cracking or other decompositionreactions occur with the formation of excessive gas and carbon. Thecarbon inactivates the catalyst and thus shortens the permissibleprocess cycle. Further, the use of or higher, the maxi-y higher contacttimes reduces the yield of the desired mono-alkylated products andincreases the yield oi undesired higher boiling polyalkylated products.

The exact temperatures to be employed depends primarily upon the type ofalcohol utilized in the process. In general, the primary alcohols aremore diillcult to react than are the secondary alcohols, and thesecondary alcohols are more dimcult to react than are the tertiaryalcohols. To compensate for this property oi the alcohols, thetemperature to be employed in the present process is adjustedaccordingly. For example, when using primary alcohols the temperature tobe employed should be within the range oi from about 500 F'. to about850 Il'. When using secondary alcohols the temperature should be withinthe range o! from about 400 F. to about 150 I". When employing tertiaryalcohols the temperatures should be within the range of from about 300l". to about 650 l".

The alcohol and aromatic utilized in the present invention need not beof purity but may contain other compounds in admixture therewith. Ingeneral, however, if it is desired to obtain a particular alkylatedproduct, certain compounds should be excluded. For example, if it isdesired to produce mono-ethylbenzene, the alcohol fraction utilizedshould not contain propyl, butyl, or higher boiling alcohols, nor shouldit contain propylene, butylene, or higher boiling oleilns. Since thehigher boiling alcohols and olefins react more readily than the ethylalcohol, the product will contain such higher boiling alkylatedaromatica which are not desired in the particular operation. However, asa general statement. more emcient operation is obtained when utilizingreactant fractions of higher purity.

As heretofore mentioned, the alcohol probably undergoes dehydration towater and olefin. Substantially complete dehydration of the alcohol iseil'ected under the conditions of operation and the eiliuent from thereaction zone does not con tain any alcohol. However, the products maycontain some unconverted oleflns which have not reacted with thearomatics, and as a particular feature of the present invention, theunreacted oleilns are dissolved ln the aromatica and are recycled to thereaction zone for further conversion therein. This method ci operationis particularly advantageous when lower boiling alcohols are utilizedas. for example. ethyl alcohol. When using ethyl alcohol, the reactionproducts will contain some ethylene, and by dissolving the ethylene inthe aromatics for recycling, the use of expensive compressors or thelike to recycle the ethylene is eliminated, since the ethylene dissolvedin the benzene may be readily pumped back to the reaction zone forfurther conversion therein.

The molal ratio of benzene to alcohol introduced from an outside sourceand recycled oleiin should be within the range oi from about 2:1 inabout 20:1, anu preferably within the range of from about 4:1 to about16:1. This molal ratio should not be less than about 2:1 since some ofthe advantages of the present invention are not obtained with lowerproportions of benzene to alcohol and olefin. On the other hand. the useof molal ratios to alcohol and recycled olefin in excess of 20:1produces no additional benefit but instead increases the size and costof plant equipment beyond practical proportions.

As to the method of operation, a particularly suitable method is todispose the catalyst in one or more reaction zones and to pass thearomatics and alcohols in contact therewith under the desiredtemperature, pressure. and time. This is oi the type known as xed bedand is a familiar method of operation. The reaction zones shouldlikewise contain provision for introducing and removing anoxygen-containing gas so that, when the activity of the catalyst becomesspent beyond a practical extent, the oxygen-containing gas may beintroduced thereto under the proper conditions of operation to effectcombustion and removal of the deposits on the catalyst. In commercialoperations at least two chambers are employed, one chamber beingutilized for conducting the process reaction while the catalyst in theother chamber is at the same time undergoing regeneration.

In commercial operations it is also the practice to utilize some sort oftiming mechanism whereby switching of the zone of process and the zoneoi' catalyst regeneration may be effected automatically. The length ofthe process cycle, that is the time a bed of catalyst is utilized forprocessing prior to regeneration, will depend upon the amount of carbonand other material deposited on the catalysts, which, in turn, willdepend upon the particular aromatics and alcohols being processed.

It is also within the scope of the invention, when desired, to introducethe alcohol from an extraneous source and/or the olen dissolved in thearomatic fraction at one or a plurality of intermediate points in thereaction zone. The use of this procedure will depend upon the ratio ofolens to aromatics utilized in any particular operation, and in certaincases may have the advantage of minimizing olen polymerizationreactions.

Another type of operation which may be utilized commercially is that nowknown in the art as iluid operation. In this method of operation thecatalyst in tnely divided condition is carried into a reaction zone bymeans of one or more of the reactants. The ow in the reaction zone is socontrolled that the converted and unconverted reactants pass into andthrough the resist primarily of ics, some higher boiling aromaticcompounds, and unreacted aromatica and olens. The products thefractionating zone and are conditions to dissolve substantially all ofthe unreacted olcn in the aromatic.

The aromatic hydrocarbons containing the dissolved olefin may then bereadily pumped back to the reaction zone for further conversion therein.

One method of conducting our process is illustrated in the accompanyingdiagrammatic drawing which is introduced for the purpose of furtherillustrating the novelty and utility of the present invention but notwith the intention of unduly limiting the same.

Referring to the drawing,

Although two such reactors are shown in the drawing, it is understoodthat one or three or more of such reactors may be employed within thescope of the present invention.

The aromatic hydrocarbon at a suitable temperature and pressure, may beintroduced to the process through line i, while the alcohol, like- Wiseat a suitable temperature and pressure, may

line 2 and directed through line 3 containing valve 4 into line i. Thecommingled charge may then be directed either through line 5 containingvalve 6 to reactor A or through line 'I containing valve 8 to reactor B,

reaction products are withdrawn either from reactor A through line i3containing valve Il, or from reactor B through line I5 containing valvei6, as the case may be, and then are directed through line I3 intofractionator i1.

While the reactants are being supplied to one reactor, a suitableoxygen-containing gas is supplied to the other reactor in order toei'lect regeneration of the catalyst. The oxygen-containing gas isintroducd through line I8 be directed through line zones A and B. Thisfraction may be directed through line l2 containing valve 3l -ceiver I1through line It isprcferablysumciontlvhlghsothattheolenn will bedissolved in the large excess ci aromatic hydrocarbon employed. ingdissolved olenn may be withdrawn from recontaining valve Il to pump l0,by means ci which a portion thereof may be recycled by way oi line Ilcontaining valve I! to the upper portion of fractionator H to serve as acooling and refluxing medium therein, while the remaining portion ofaromatic and oleiln may be directed through line I3 containing valve uinto line l, whereby it is supplied in the manner heretofore set ier-th.

Water may be drained from receiver 31 through line 45 containing valve4B. Receiver 3l is also provided with conventional gas release line 41containing valve l0.

The present invention is particularly applicable to the alkylaticn oibenzene with ethyl alcohol to produce mono-ethylbenaene. By operating inaccordance with the teachings herein, increased yields oimono-ethylbenzene are obtainable. The ethyibenncne may be dehydrogenatedto produce styrene, which styrene may be utilized as one ci thereactants in the preparation of synthetic rubber.

' The following example ci one operation is given for the purpose cifurther illustrating the invention but not with the intention oi' undulylimitlng the same.

This example relates to the reaction of bennene with ethyl alcohol inthc presence ci a fixed bed of catalyst comprising silica and alumina ata temperature of 700 F. under a pressure ci 900 poundspersquareinch.Theratiooibenaeneto ethyl alcohol and recycled ethylene is :1. The 3.4minutes. The eiilucnt from the reaction none comprisesmono-ethylbenzene, higher boiling poly-ethylated benzene, unreactedbenaene. and ethylene. The benzene and ethylche are cooled toatmospheric temperature and are condensed under a pressure oi 000 poundsper square inch. The benzene. g dissolved ethylene, is recycled to thereaction sone for further conversion therein. Water is present in thealulated products and is separated thererom.

We claim as our invention:

i. A process for producing substantial yields ot aikylated aromatichydrocarbons which comprises subiecting aromatic hydrocarbons and alwitha composite catalyst comprising precipitated silica and alumina ior atime of contact oi' not more than l5 minutes.

2. A process tor producing mono-ethylbcnrene which comprises subjectingbenzene and ethyl alcohol to contact with a composite catalystcomprising precipitated silica and precipitated alumina tor a time ofcontact o! not more than minutes.

3. A process lor producing substantial yields of alkylated aromatichydrocarbons which comprises subiechng aromatic hydrocarbons and aprimary to contact with a composite catalyst containing precipitatedsilica and alumina at a tcmof from about 500 F. to about 050 F.

` for a time of contact ci not more than l5 minutes.

4. A process for producing substantial yields of alkylated aromatichydrocarbons which comprisa subjecting aromatic hydrocarbons and asecondary alcohol to contact with a composite catalyst containingprecipitated silica and alumina at a temperature oi from about 400 F.toabout'l50 F.iora\time cipontactcimt m than 15 mmm,

5.`A proces for producing substantial yields comprises suoiectingaromatic hydrocarbons and a tertiary alcohol to contact with a compositecataiyst containing precipitated silica and alumina at a temperature o1irom about 300 F. to about 050 F. for a time oi contact of not more thanib minutes.

o. A process for producing substantial yields of alxylateo aromatichydrocarbons which comprises subiecting aromatic hydrocarbons and aprimary alcohol to contact with a composite cataiyst containingprecipitated silica and precipitated alumina at a temperature ci iromabout 500 F. to about 850 F. under a. pressure of from about 200 toabout 2000 pounds per square inch i'or a time o! contact oi not morethan 1b minutes.

'n'. A process for producing substantial yields of alkyiated aromatichydrocarbons which comprises snbieoting aromatic hydrocarbons and asecondary alcohol to contact with a composite catalyst containingprecipitated silica and precipitated alumina at a temperature o! iromabout 400" F. to about ri50 F. under a pressure oi from about 200 toabout 2000 pounds per square inch ior a time of contact ci not more thanl5 minutes.

8. A process ior producing substantial yields oi alkylatcd aromatichydrocarbons which comprises taining precipitated silica andprecipitated alumina at a temperature oi trom about 300 F. to about 650"F. under a pressure of from about 200 to about 2000 pounds per squareinch ior a time ot contact ci not more than l5 minutes.

9. A process for producing substantial yields oi alwlated aromatichydrocarbons which comprises subjecting aromatic hydrocarbons andalcohols to contact with a synthetically prepared composite mass ofsilica and an oxide selected from the group consisting oi alumina,zirconia, magnesio and thoria for a time ci contact ot not more than 15minutes.

10. A process for producing mono-ethylbenzene which comprises subiectingone molecular proportion or ethyl alcohol and from about 2 to about 20molecular proportions of benzene to contact with a composite catalystcomprising alumina and precipitated silica at a temperature of fromabout 500 F. to about 850 F. under a pressure of from about 200 to about2000 pounds per square inch for a time of contact of not more than l5minutes.

11. A process ior the production oi mono-ethylbensenc which comprisesreacting benzene, ethyl alcohol, and ethylene at a temperature oi fromabout 500 F. to about 850 F. 'under a pressure oi from about 200 toabout 2000 pounds per square inch for a time of contact of not more thanl5 minutes in the presence of a composite catalyst comprising aluminaand precipitated silica in a reaction zone, said reaction comprisingdehydration of the ethyl alcohol to water and ethylene and alkylation cithe benzene by ethylene, separating the reaction products into alkylatedbenaene and unreacted ethylene and benzene under a pressure oi fromabout 200 pounds to about 2000 pounds per square inch in order todissolve said unreacted ethylene in said benzene. and recycling saidbenzene and dissolved ethylene to the reaction sone for furtherconversion therein, the ratio of benzene to ethylene in said reactionacne being two to twenty molecular proportions ci benacne tc onemolecular proportion o! ethyl alcohol and ethylene.

6 a,se4,sos

12. synthesizing process which comprises re- 14. A process forsynthesizing hydrocarbons acting an aromatic hydrocarbon with analcowhich comprises reacting an aromatic hydrocarhoi under reactionconditions in the presence ot bon with an alcohol under reactionconditions in `a precipitated silica catalyst. the presence o1' acomposite catalyst comprising 13. Asynthe'sizing process which comprisesre- 5 precipitated silica and a metal oxide selected acting an aromatichydrocarbon with an alcohol from the group consisting o! alumina.zirconia, under reaction conditions in the presence of a thoria andmagnesia.

catalyst comprising precipitated silica and a metal CHARLES L. THOMAS.oxide selected from the group consisting of aiu- VLADIMIR HAENSEL. mina,zirconia, thoria and magnesia. l0

Disclaimer 2,384,505.-0harle= L. Thomas and Vladimir Hunsel, Chico, Ill.TREATMENT on' HYDRocARBoNs. Patent dated Sept. 11, 1945. isclaimer filedDec. 7, i949, by the assignee, Universal Oil Products Company. Herebenters this disclaimer to claim 1 of said patent.

[yc'ial Gazette January I7, 1950.]

6 a,se4,sos

12. synthesizing process which comprises re- 14. A process forsynthesizing hydrocarbons acting an aromatic hydrocarbon with analcowhich comprises reacting an aromatic hydrocarhoi under reactionconditions in the presence ot bon with an alcohol under reactionconditions in `a precipitated silica catalyst. the presence o1' acomposite catalyst comprising 13. Asynthe'sizing process which comprisesre- 5 precipitated silica and a metal oxide selected acting an aromatichydrocarbon with an alcohol from the group consisting o! alumina.zirconia, under reaction conditions in the presence of a thoria andmagnesia.

catalyst comprising precipitated silica and a metal CHARLES L. THOMAS.oxide selected from the group consisting of aiu- VLADIMIR HAENSEL. mina,zirconia, thoria and magnesia. l0

Disclaimer 2,384,505.-0harle= L. Thomas and Vladimir Hunsel, Chico, Ill.TREATMENT on' HYDRocARBoNs. Patent dated Sept. 11, 1945. isclaimer filedDec. 7, i949, by the assignee, Universal Oil Products Company. Herebenters this disclaimer to claim 1 of said patent.

[yc'ial Gazette January I7, 1950.]

